iWalk: Cambridge's quietest start-up?

I'd really heard absolutely nothing about iWalk, a Cambridge start-up that has been around for a couple years now, until I was doing some research for a robotics panel this week at MIT.

One of my panelists was MIT prof Hugh Herr, who also serves as founder and chief scientific officer of iWalk. The company is commercializing a robotic prosthetic device developed in Herr's lab that does the job of a foot and ankle for people who no longer have their own. They call it "PowerFoot One," and according to the Web site:

"Two powerful microprocessors and six environmental sensors evaluate and adjust ankle position, stiffness, damping and power thousands of times a second. Control algorithms generate human-like force while traversing level ground, slopes and stairs, providing active amputees with near-normal gait and lower energy expenditure compared to state-of-the-art passive prosthetics."

Seed funding for the company came from Media Lab founder Nicholas Negroponte and other angel investors. HBS prof Bill Sahlman serves on iWalk's board.

Herr told me that two years ago, the company raised $5 million from WFD Ventures in New York. Right now, Herr said, iWalk is trying to raise another $7 or $8 million to get the first product finished and ready for sale.

In addition to Herr and CEO Richard Greenwald, the start-up has five employees, I'm told.

More on the technology here.